This invention relates to the processing of film media in phototypesetting where large quantities of various widths of light sensitive print media is transported from a supply magazine and over a cathode ray projection system and into a take-up magazine. It is the take-up spindle with which this invention is particularly concerned, and it is film media in the form of print media or the like that varies from 75 mm to 315 mm in width, and in lengths up to 400 feet that is to be accommodated thereby. Such a take-up magazine is sizable, having a seven to eight inch substantially square cross section, and having a length to receive 315 mm wide media, for example.
Heretofore, the take-up spindle has been slotted diametrically to accept the film media leader, and of a sizable diameter of 2.44 inch and constructed of two complementary semi-circular solids of hardwood. Such a spindle requires approximately eleven inches of media wrapped around it in order to establish a secure connection, as follows: The film media is entered into the magazine and the leader thereof is inserted through a coextensive diametric slot so as to project from the opposite side a distance about equal to the spindle diameter, an end portion approximately six inches in length. The projecting end portion of the leader folds over and against the spindle as it is rotated a full turn of 360.degree. in order to secure the connection; and all of which requires approximately eleven inches of leader wrapped around the take-up spindle. It is a general object of this invention to reduce film media leader length, since its lineal cost is great. With the present invention but three to four inches of film media is lost to the take-up spindle as a leader.
The take-up spindle of this invention has several automatic features and one of which satisfies the object of restricting leader length, as distinct from the prior art slotted spindles having no leader length control. With the present invention, the spindle is a tube slotted coextensively through one outside wall thereof for insertion of the film media leader and the length of which is restricted by engagement with the diametrically opposite and imperforate inside wall thereof. The spindle interior has a diameter substantially less than the standard exterior diameter of 2.44 inch, due to its wall thickness, and in practice limits initial leader insertion to approximately two inches. Unobviously, however, initial rotation of the spindle withdraws about half of said two inch leader and to the end that the final leader portion entering the spindle interior is only about one inch. Withdrawal of said half portion is inherent in lost motion as and when an anchor means is operated through initial turning of the spindle.
The spindle of this invention has another automatic feature and the object of which is to provide inherent operation of the said releasable anchor means, responsive to the presence of film media inserted into the slot and to the rotation of the spindle a part turn of 90.degree. to 180.degree. (compare FIGS. 1 and 5). With this invention there is an anchor pawl that snubs the media with a locking action that is releasable, and it is the media that wraps over said anchor pawl to actuate it, and conversely to unwrap and expose it for release. In practice, 30.degree. or slightly more and up to 45.degree. of the spindle rotation determines the functional effect of said anchor pawl (see FIG. 4). Consequently, only two inches, more or less, of leader is sacrificed in order to reliably secure the film media to the take-up spindle.
It is an object of this invention to provide an improved take-up spindle of the type under consideration, and which can be manufactured at reduced cost. The prior art hardwood spindles of slotted configuration have cost approximately a third more to manufacture than the improved spindle herein disclosed. With the present invention, the spindle tube is extruded of aluminum, or molded of like material having the required longitudinal features and so that machining or finishing is confined to the ends thereof. Another object of this invention is to retain the inertial characteristics of such spindles as they have been used, so that its use in motor driven phototypesetters is not adversely affected. Further, it is an object of this invention to provide a take-up spindle as thus far described that operates inherently without difficulty and with no requirement for special training or instruction to the operators of the phototypesetter equipment.